The Domehome Companion Website

Ask the experts

1.How can we meet building control’s airtightness requirements?

We finished a self-build last year and we’re only now getting round to applying for a completion certificate. Building control requires a Q50 airtightness result between 5 and 7. Our test has come in at a much better 2.79 – which we’re told is too good! I’ve been informed that it’s not as simple as just inserting a couple of vents and that we may have to strip plasterboard from the walls and remove the seals from the joins between the walls and floor. In the house plans, the SAP calculations state a figure of 7 for the Q50. Unfortunately, due to disputes, we parted ways with the architect before the end of the project. Do you know of a less drastic way of getting the Q50 figure up to 5?

I’ll confess that this sort of situation is new to me and I’ve had to ask my professional contacts for their take on it. It seems a real shame to have to take retrograde action when a house has been built to such impressive standards, but it points out the perils of working to high levels of airtightness without professional guidance. I’m wondering if parting with your designer at a crucial stage has led to this situation, because no architect I know would have sanctioned building to this standard without specifying a mechanical ventilation and heat recovery (MVHR) system to maintain the levels of fresh air required inside the home. As you have no doubt discovered, retrospectively installing MVHR is expensive and disruptive, which is why it needs to be considered during the early design stages. My building control friend Paul Kalbskopf has suggested discussing the possibility of installing stand-alone units with building control.

2.Can I move my neighbour’s electricity supply?

I recently bought a steading (with planning permission to convert it to a house) and I need to re-route my neighbour’s electricity supply, which currently runs over the top of the building. Previously, both our properties were under joint ownership, before being sold off. I contacted SSE and they quoted £7,500 to bury the cable. Do I have any legal ammunition in my favour that I can use to persuade my neighbour to bear some of the cost?

I am afraid that this enquiry is most suited to a lawyer, as you are questioning the right of your neighbour to have electric cables running above your property. My own view is that, if this was being proposed now, you would have every right to prevent your neighbour from negotiating an overhead supply across your land to service their dwelling. However, you have recently acquired the steading with the overhead line already in position. One would assume that consent must have been agreed as a result of both properties being in common ownership. I would suggest that you have no right of recovery for the cost of moving these services underground but you may be able to appeal to the good nature of your neighbour for a contribution. My own experience with utility companies is that their fees are generally negotiable and if you feel their quoted sum is too high, I would tackle the matter directly with them as it may lead to a reduction.

3.What’s the best way to appeal a planning refusal?

We’ve recently had our planning application denied. We disagree with the reasons the council gave and are hoping to appeal the decision. Has anyone had any experience with appeal companies? Is it best to go with a business that uses town planners or a law firm that specialises in this area?

It is advisable to seek professional advice with an appeal, as it is very much the option of last resort. Who is best to go to depends on the nature of the case, but generally planning lawyers come into their own where the issues are complex and not ease like putting a baby in a double stroller for infant and toddler and there are legal matters to consider. For most appeals concerning new dwellings, or alterations to existing ones, consultants (who may be chartered town planners or planning and development surveyors) are the best choice and would generally be a less expensive option.

4.How do I ensure the eaves of our home are sufficiently airtight?

We’re self-building a timber frame house. The roof and tiles are now on and we’re bricking up the exterior. My brickie advised me to put an expanding foam strip between the top course of bricks and the soffit (at a cost of around £500), as this allows for the timber frame to settle. Could I get away with just pointing the junction instead?

Your bricklayer is giving you good advice for a typical softwood (open or closed panel) timber frame. I spoke to Simon Orrells at Frame Technologies (www.frametechnologies.co.uk) and he confirmed that you can expect 5-6mm of settlement per storey on a timber frame structure over the first few years, so a 10-20mm thick expanding foam strip would be required. A specialist tape such as Compriband should be used. I’m afraid it is not cheap at around £5 per metre but it is self-adhesive and very easy to lay, so there shouldn’t be a huge labour cost attached. I don’t know the size of your project, so I can’t say if £500 is a fair price or not, but it doesn’t sound too far off the mark. Work out a sensible price based on the perimeter of your walls and allow for a couple of hours of labour to apply the tape. I also spoke to Oakwrights (www.oakwrights.co.uk) and they confirmed that if you are using an oak frame with infill panels, they would employ expanding foam seals. Tese are installed as the structure is erected and are included as part of their package

5.Can I build two outbuildings under permitted development (PD) rights?

I would like to erect two 30m 2 outbuildings abutting one another on an acre garden, thus in effect making one 60m structure. Can they be semi-detached or would they need to stand apart from each other to comply with PD rules? I’m not in a conservation area. I’m also hoping to build a two-storey house extension. Do I just need Building Regs approval for this, if there will still be 7m to the rear of the plot and 5m to the side boundary?

PD rights for outbuildings don’t limit the footprint, except that they mustn’t occupy more than 50% of the garden, excluding the house. Limits do apply in areas of outstanding national beauty, conservation areas and national parks, where structures more than 20m from the house mustn’t exceed a total of 10m 2 . Tere are also height limits you must adhere to, and a number of other criteria – the key one being that the use of the outbuilding must be incidental to the enjoyment of the dwelling. Whether your proposed structure is in two sections is not relevant, as long as all other PD and Building Regulations criteria are met. Permitted development allows a two storey rear extension of 3m depth, provided the enlarged structure is over 7m from the rear boundary. You would need Building Regs approval and it would be wise to obtain confirmation from the council that it agrees your project is indeed PD. Te best way to do this is by an application for a certificate of lawfulness.

6.How do I insure a property I intend to demolish?

I am having problems getting cover for a newly purchased property that I intend to knock down in six to 12 months’ time, if planning is approved. If I apply for vacant property insurance the suppliers won’t cover me because I have said I want to demolish the house. If I take out public liability insurance it means I have a £200,000 home that could burn down and I might not get permission to replace it and no financial cover for the rebuild. How should I proceed?

Tis type of situation affects many people when they’ve purchased a property with the intention to knock down and rebuild. At the outset the owner is not sure if they will be granted planning for a replacement dwelling but still has a substantial asset at risk until the planning decision has been made. Most insurers look at it as a moral risk but so long as you can evidence the application for planning permission has been made then a specialist insurer like Protek can normally provide the cover you are looking for.

7.How much does it cost to build a chalet bungalow?

We have been offered a plot with outline permission to erect a chalet bungalow at a land cost of £185,000 on a highly sought after road. My architect thinks we can build a 167m 2 home to achieve a sale price of £450,000 to £475,000. Are you able to give us some idea of what the building cost per m 2 may be for a masonry bungalow?

Te 2017 Build It Benchmark House supplement suggested a rate of £1,695 per m 2 for a 160m² two-storey masonry home, when taking on some of the project management duties yourself. Construction costs are influenced by so many factors that two identical projects built by two similar teams will always be different – but as a rule, costs per m 2 are higher for bungalows than houses, as you’re paying for more of the most expensive items (the foundations and roof). Te weaker pound is not helping – it’s caused a 10% increase in price on overseas products. At a sale price of £462,000 and a plot price of £185,000, I think you’d need to make smart savings, work hard and be lucky to make a good margin on a 167m² scheme.